Re: OT: Which tool, and how, to get partial string from file?

[John Summerfield <debian@ComputerDatasafe.com.au>]

Thomas Adam wrote:

> On Fri, Aug 20, 2004 at 09:46:52PM -0500, Kent West wrote:
>  
>
> > Maybe I'm asking the wrong question.
> >
> > Here's a new question.
> >
> > How can I test to see if the word "tuber" is in the /etc/passwd file, 
> > reliably, and take an action if it is, and take a different action if 
> > it's not, in a bash shell script?
> >    
>
> You won't need to read the file, use "getent passwd":
>
> getent passwd | grep tuber
>
> If 'tuber' is the username, you can shorten this to:
>
> getent passwd tuber
>
> or even:
>
> [ -n "$(getent passwd tuber)" ] && tuber exists || tuber does
> not exist
>  
kowari:~# getent passwd john
kowari:~# getent passwd summer
summer:x:1001:1001:John Summerfield:/home/users/summer:/bin/bash
kowari:~# getent passwd John
kowari:~#

OTOH

kowari:~# grep -qiw john /etc/passwd && echo Found John   
Found John
kowari:~# grep -qiw jon /etc/passwd && echo Found John
kowari:~#

For more, man grep

--

Cheers
John

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